An INDO-MO Study of the Conformations and Electronic Structures of HCHOH+, CH3CHOH+, (CH3)2COH+, HCO2H2+, CH3CO2H2+, and CH3OH2+

Abstract
INDO-SCF calculations were performed on several protonated compounds, HCHOH+ CH3CHOH+, (CH3)2COH+, HCO2H2+, CH3CO2H2+, and CH3OH2+, and also on the corresponding parent molecules in order to investigate their conformations and electronic structures. Geometric optimization resulted in reasonable conformations as compared with the previous ab initio calculations and in sufficient magnitudes of the energy differences between the rotational isomers in comparison with the NMR observations. The change in the electronic structures of the parent molecules due to protonation is also discussed by paying attention to the polarization caused by electron delocalization, hybridization at the proton-bound oxygen atom, the protonation energy, and the ionization potentials.